Submarine direction finder



Sept-18, 1928.

. "w. RUDOLPH. ETA].

SUBMARINE DIRECTION FINDER Filed Oct. 24. 1922 .w. RUDOLPH ET'ALSUBMARINE DIRECTION FINDER {Sheets- Sheet 2 Filed Oct. 24, 1922INVENTORS Wilhelm Rudolph.

Gustav Wolff? plants are arranged within the ship or direct- NET.easamscmr mm nasx'raa Immune,- or m, e .r I I l surname nmncrionFINDER.

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Application filed 0mm: 24, 1922, Serial ire-596390, and in GermanyOctober 9, i922.

The invention relates to sound receiving plants in connection withships, adapted to ascertain. the direction. of arriving soundv waves. Ithas been found that disturbances-- of diiferent kinds arise if thereceivers of such ly in the wall of the ship or in the near vicinity toit. These disturbances are caused by the proximity of the air'filledvolume of the body 1o ofthe ship itself, the sound waves being lessenedby this volume; besides this interference occurs due to" soundwavesarriving directly through the water to the receivers coacting withsound waves transmitted through the iron walls of the ship; anotherdisadvantage arises from deflection and refllelction'of sound waves bythe body of the s p. a

According to the invention the receivers of :30 a sound directionascertaining plant are. ar-

marines it is to be preferred to mount them above the upper deck.Preferably they are" ranged outside thehorizontal sound shadow of thebody of the ship and practically open to the arriving sound fromall'directions, and rigidly connected to the shi On normal ships thereceivers may be arranged below the bottom of the ship, on subconnectedto rigid brackets and enveloped by a rigid hollow casing filled withwater and 4 shown in Fig. 1.

rigidly connected with the ship. Openings in the wall of this casing mayallow the water of the sea to enter, and the casing itself preferablymay be of stream line shape. Figure 1 shows a sound directionascertaining plant upon a submarine boat with two receivers above theupper deck and one receiver upon the tower.

Figure 2 shows a plan view of the' boat In Figure 1 the watertight bodyof the submarine is represented by 3. The'outer shell 1 of the boatcarries the hollow casin 9 the =1nner space of which communicates t rouh 5 openings 4, 4 with the outside water; Withm this casmg two receivers6, 6 are mounted upon the upper ends of brackets which are rigidlconnected to the outer shell l'of the main ody 3.

The pair of receivers 6, 6 permits the operator to ascertain thedirection of the arriving sound by any of the well known base-methods;-i. e.,,by measuring the time interval between the arriving of one andthe same sound "65. at the two receivers, or-byobserving maxima alldirections.

for ships,

or minima' of sound caused b interference of g sound waves, or bysensing t e direction.

Another receiver 7 adapted to be used alone for ascertaining thedirection of sound (that is, a directionally responsive receiver) isarranged abovethe top of the tower 8 of the submarine within a similarcasing as described before. Such a receiver is shown,-for exampggzinPatent No. 1,636,576, issued July 19, I V

Figure 2 shows the same apparatus as Figure 1 but in plan view. Fromthis, figure it can be seen that the tower 8 would'not exercise anyappreciable screening efi'ect upon the receivers 6 since the latter areplaced in the bow of the vessel whereas the tower is amidships.

The sound shadow effect of the conning tower upon the receiver 6 couldatmost be the small angle included between the lines AA in Figure 2 butpractically due to difi'raction at the edges of the tower and othercauses would be entirely negligible. The receivers therefore are eachand all substantially freely accessible to sound waves com'injg from allhorizontal directions. Receivers so mounted may be said to besubstantially outside the horizon tal sound shadow of the ship.

The different methods of ascertaining the direction of sound are not theobject of the invention; instead, the most important feature of theinvention is the fact, that the receivers themselves are free ofdisturbances caused by the vicinity of the body of the ship, and arefreely accessible to sound waves coming through the water;

What we claim is:

1. In combination with a ship, a sound receiver adapted to receivesounds from substan- .tially all directions, means for mounting saidreceiver at a fixed distance from the ship and for firmly fixing itthereto, said receiver being positioned so as to be freely accessible tosound waves from all horizontal directions.

2. In a submarine sound receiving plant as sociated with a ship andadapted to ascertain the direction of sound waves, a pluralit of soundreceivers, means for mounting sai receivers at a fixed distance from theships body and rigidly connecting them thereto, a-waterfilled casingsurrounding said receivers said receivers bein positioned so as to befreely accessible to t e arriving soundwaves from 3. Submarine soundreceiving equipment comprising a'plurality of sound: re- 11o ceivers,means for mounting said receivers at tions and substantially free ofdisturbances a'fixed distance from the body of the ship and arising fromthe fin'oximity of the ship and 10 rigidly connecting them thereto,awater-filled its motion throug the water. casing surrounding thereceivers, said re- In-gte's'timony whereof .we aflix our signa- 5ceivers being positioned substantially outside ture's. v

of the horizontal sound shadow of the ship, whereby the receivers willbe freely accessible- WILHELM RUDOLPH. to the arriving sound waves fromall direc- GUSTAV WOLFF.

